Romex outdoor application

letgomywago

Senior Member
Location
Washington state
Occupation
residential electrician
So flush mounted exterior boxes, inside the building envelope, are getting water in them in your world? That's not happening in mine.
I'm pretty sure every outdoor rated cover comes with either a gasket and or 3r style drain. The gasket should keep water out if the outside building envelope is sound.
 

garbo

Senior Member
So flush mounted exterior boxes, inside the building envelope, are getting water in them in your world? That's not happening in mine.
My area has a high humidity most of the year and that along with nobody ever seals even a flush mounted box that causing air to flow thru and cause condensation. Years ago I started to use fiberglass wall cases on all boxes that supplied not only outdoor luminares & receptacles but on interior walls that were on inside of exterior walls. Used bathroom silicone caulk ( not suppose to mildew ) to seal cable entrance and finished edge where box meets sheetrock .
 

garbo

Senior Member
No. NM cable has paper wrapped around the ground conductor and exterior jacket is never approved for damp or wet locations like UF cable. Like I posted earlier that I live in a area with high humidity that guess contributes to type NM cable installed into back of exterior box to have the paper on ground conductor to become damp or wet. Firmly believe that if you enter the rear of a FS or FD box and use a quality chalk like silicone to seal off end of type NM cable it should be allowed. Installed a quality aluminum FS box on the outside of my concrete foundation for a receptacle over 45 years ago and silicone end if NM cable and box had been covered over with snow for a week several times but every 5 years or so when I remove plate for an inspection interior of box is bone dry and no signs of bugs.
 

BarryO

Senior Member
Location
Bend, OR
Occupation
Electrical engineer (retired)
At an IAEI meeting an inspector told us that NM ( Romex ) is never allowed outdoors or even to enter the rear of a pancake box for an outdoor luminare because its not rated for damp or wet locations.. Have the old cloth covered romex feeding an outdoor luminare. When I replaced the luminare a few years ago wire was in great shape. House was built 60 years ago. Told us to only use UF cable to feed all outdoor luminare & receptacles.
In the Southwest there are very many (probably millions) of residential breaker panels located outside, with the NM for the branch circuits running directly to the panel.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
Almost every residential panel in Southern California is a meter main outside.

As will be everywhere with the outside disconnect requirement. But a single 2 pole breaker is a lot different than a panel full of GFCI and AFCI breakers that are susceptible to damage from moisture and temperature. Also, consider the homeowner having to go outside in the rain, snow or darkness to a panel in the shrubbery to find if a breaker has tripped.

No, outdoor panels should be outlawed!

-Hal
 

SSDriver

Senior Member
Location
California
Occupation
Electrician
As will be everywhere with the outside disconnect requirement. But a single 2 pole breaker is a lot different than a panel full of GFCI and AFCI breakers that are susceptible to damage from moisture and temperature. Also, consider the homeowner having to go outside in the rain, snow or darkness to a panel in the shrubbery to find if a breaker has tripped.

No, outdoor panels should be outlawed!

-Hal
It's been this way here forever. I agree it would be better inside but it really hasn't been an issue in our climate. GFCIs seem to last fine. AFCIs don't work regardless.
 

garbo

Senior Member
Ouch!

-Hal
With all the heat and sure bugs & spiders in outdoor panels any guess on how long the average say 15 & 20 amp single & two pole plug in circuit breakers last?. In my area we have over 60 year old panels with all the original breakers still operating. They are in basements that are heated and most likely never in a temperature below 60 degrees or hotter then 90 degrees. In my 60 year old development they installed ITE Pushmatic panels and had done free work in at least a dozen of my neighbors homes and only had to replace a 30 amp two pole breaker for a central AC unit. Always keep some in stock for this. Of course neighbor cried when he paid thru the nose at local box store for that Pushmatic breaker that I asked him to replace for the one that I installed during a heat wave.
 
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